A lithium mica calcination apparatus and a method for preparing lithium carbonate and producing by-products.

Abstract

This invention provides a lithium mica roasting apparatus and a method for preparing lithium carbonate and producing by-products. The lithium mica roasting apparatus includes: a roasting furnace and a base; a discharge assembly installed on the roasting furnace for discharging materials from inside the furnace; and a receiving box installed at the bottom of the discharge assembly, on which a stirring assembly is mounted. The lithium mica roasting apparatus and method for preparing lithium carbonate and producing by-products provided by this invention achieve a turning effect during material roasting through the stirring assembly, improving roasting uniformity and thus enhancing the quality of metal recovery. The receiving box also provides a sealing effect during furnace discharge, reducing the entry of cold air into the furnace and preventing severe furnace temperature loss, resulting in energy savings and improved metal recovery efficiency.

Description

Technical Field

[0001] This invention relates to the field of hydrometallurgical processing of lepidolite, and more particularly to a lepidolite roasting apparatus and a method for preparing lithium carbonate and producing by-products. Background Technology

[0002] Lithium, known as "white petroleum," is a key strategic metal for the development of the new energy industry. With the rapid development of the new energy vehicle industry, the research and application of lithium extraction technology from lepidolite has received increasing attention. Currently, the main methods for lithium extraction from lepidolite include the sulfate method, the sulfuric acid method, the limestone calcination method, and the chlorination roasting method.

[0003] Current lithium extraction processes generally focus only on lithium recovery, while high-value elements such as rubidium, cesium, aluminum, and potassium, which are associated with lepidolite, are mostly wasted in waste residue or waste liquid. Rubidium and cesium salts, as important rare and precious metal materials, have irreplaceable application value in high-tech fields such as high-precision atomic clocks, quantum physics research, ion thrusters, optoelectronic materials, lithography machines, and aerospace.

[0004] The sulfate process is widely used in industry, but it has significant drawbacks: producing 1 ton of lithium carbonate generates approximately 15-21 tons of smelting slag, which is large in volume and contains heavy metals such as beryllium and thallium, posing an environmental pollution risk due to tailings disposal; furthermore, the process requires the addition of large amounts of sodium and potassium sulfates, resulting in high sodium and potassium concentrations in the leachate, increasing the burden on subsequent purification. While the traditional sulfuric acid process can achieve high lithium leaching rates, it suffers from high roasting temperatures (typically above 900℃) and high energy consumption.

[0005] In related technologies, traditional lithium mica roasting devices discharge material by opening the feed inlet after roasting. As the material falls, a large amount of cold air enters the furnace body through the feed inlet, which can easily lead to furnace body temperature loss and increase temperature loss.

[0006] Therefore, it is necessary to provide a lithium mica roasting apparatus and a method for preparing lithium carbonate and producing by-products to solve the above-mentioned technical problems. Summary of the Invention

[0007] This invention provides a lithium mica roasting apparatus and a method for preparing lithium carbonate and producing by-products, which solves the problem that a large amount of cold air enters the furnace body through the discharge port during material discharge, which easily leads to furnace body temperature loss and increases temperature loss.

[0008] To solve the above-mentioned technical problems, the lithium mica calcination apparatus provided by the present invention includes: a calcination furnace and a base;

[0009] A discharge assembly is installed on the roasting furnace and is used to discharge materials inside the roasting furnace.

[0010] A receiving box is installed at the bottom of the discharging assembly. A stirring assembly is installed on the receiving box. The stirring assembly passes through the discharging assembly and extends into the interior of the roasting furnace. The stirring assembly is used to stir the materials inside the roasting furnace.

[0011] A heat dissipation component is installed on the receiving bin and is used to dissipate heat from the material discharged into the receiving bin.

[0012] A fixed box is installed on the base, and the top of the fixed box is fixedly connected to the receiving box. A clearing component is installed on the fixed box, which passes through the receiving box and extends into the receiving box. When the discharging component discharges material, the clearing component is used to clear the blockage.

[0013] A drive assembly, which is mounted on the fixed housing.

[0014] Preferably, the top of the roasting furnace is equipped with a feeding trough, a burner and a flue gas exhaust pipe, and the left side of the receiving box is equipped with a box door.

[0015] Preferably, the discharge assembly includes a discharge trough, a sealing strip, a sealing plate, a displacement frame, a telescopic structure, and an L-shaped frame. The discharge trough is fixed between the roasting furnace and the receiving box. The sealing strip is fixed to the left side of the inner wall of the discharge trough. The sealing plate is slidably connected to the discharge trough. The displacement frame is fixed to the sealing plate. The telescopic structure is installed on the displacement frame. The L-shaped frame is slidably connected to the displacement frame.

[0016] Preferably, the telescopic structure includes a piston cylinder, a piston block, a first elastic element, and a piston rod. The piston cylinder is fixed to the displacement frame, the piston block is slidably connected inside the piston cylinder, the first elastic element is disposed between the piston cylinder and the piston block, the piston rod is fixed to the piston block, and one end of the piston rod is fixed to the L-shaped frame.

[0017] Preferably, the stirring assembly includes a stirring shaft, a first bevel gear, and a stirring disc. The stirring shaft is rotatably connected to the receiving box, the first bevel gear is fixed to the bottom end of the stirring shaft, and the stirring disc is fixed to the outer surface of the stirring shaft.

[0018] Preferably, the heat dissipation assembly includes a heat dissipation groove, a filter screen, a mounting bracket, a sliding block, a second elastic element, a baffle plate, a through hole, and an inclined block. The heat dissipation groove is fixed to the receiving box, the filter screen is installed in the heat dissipation groove, the mounting bracket is fixed to the receiving box, the sliding block is slidably connected to the mounting bracket, the second elastic element is disposed between the mounting bracket and the sliding block, the baffle plate is fixed to the top of the sliding block and fits against the heat dissipation groove, the through hole is opened on the baffle plate, and the inclined block is fixed to the baffle plate.

[0019] Preferably, the unblocking assembly includes a connecting frame, a sliding plate, a third elastic element, a connecting rod, a connecting plate, a fixing ring, an unblocking cone, a sleeve, a cam, and a positioning sleeve. The connecting frame is fixed inside the fixing box, the sliding plate is slidably connected inside the connecting frame, the third elastic element is disposed between the connecting frame and the sliding plate, the connecting rod is fixed to the sliding plate, the connecting plate is fixed to the top end of the connecting rod, the fixing ring is fixed to the connecting plate, the unblocking cone is fixed to the fixing ring, the sleeve is rotatably connected to the connecting frame, the cam is fixed to the outer surface of the sleeve, and the positioning sleeve is fixed to one end of the sleeve.

[0020] Preferably, the drive assembly includes a pusher, a movable plate, a drive rod, a second bevel gear, a positioning block, a connecting plate, and a drive member. The pusher is fixed to the fixed box, the movable plate is fixed to the output end of the pusher and slidably connected to the fixed box, the drive rod is rotatably connected to the movable plate, the second bevel gear and the positioning block are both fixed to the outer surface of the drive rod, the connecting plate is rotatably connected to the drive rod and slidably connected to the base, the drive member is mounted on the connecting plate, and the output shaft of the drive member is fixedly connected to the drive rod.

[0021] This invention also provides a method for preparing lithium carbonate from lepidolite and producing by-products, comprising the following steps:

[0022] Step S1: The crushed and ball-milled lithium mica concentrate is mixed with dilute sulfuric acid and roasted at low temperature in the roasting device to obtain roasted clinker;

[0023] Step S2: Stir and leach the roasted clinker. After leaching, perform solid-liquid separation to obtain leaching residue and leaching brine containing lithium, aluminum, potassium, rubidium, and cesium.

[0024] Step S3: Wash the leaching residue twice to obtain first wash water, second wash water and washed residue. Return the first wash water to step S2 for leaching, and repeat the second wash water as the first wash.

[0025] Step S4: Add potassium hydroxide to the leaching brine obtained in step S2 to adjust the pH to 2-3, then cool to 18-20℃ and crystallize at a constant temperature to precipitate rubidium and cesium alum crystals. Filter to recover rubidium and cesium vanadium. Continue to cool the filtrate to 0-8℃ and crystallize at a constant temperature to precipitate potassium alum crystals. Filter to recover potassium alum to obtain filtrate A.

[0026] Step S5: Add calcium oxide slurry to filtrate A, adjust the pH to 6-6.5, stir the reaction to precipitate iron ions and residual aluminum ions in the form of hydroxides, and filter to obtain iron-aluminum-fluorine filter residue and filtrate B.

[0027] Step S6: Continue to add calcium oxide slurry to filtrate B, adjust the pH to 11.5-12, stir the reaction to precipitate magnesium ions and manganese ions into magnesium hydroxide and manganese hydroxide, and filter to obtain magnesium-manganese filter residue and filtrate C.

[0028] Step S7: Add potassium carbonate to filtrate C, stir to react, and react with calcium ions in the solution to form calcium carbonate precipitate. Filter to obtain calcium-containing filter residue and filtrate D.

[0029] Step S8: The filtrate D is deeply purified by passing it through an ion exchange resin to remove residual trace impurity metal ions, resulting in a pure lithium sulfate solution E.

[0030] Step S9: Carbon dioxide is introduced into solution E at room temperature to carry out a carbonation reaction. After the reaction is completed, the temperature is raised to 80-95℃ and the reaction is carried out again to generate lithium carbonate precipitate. After filtration, washing and drying, battery-grade lithium carbonate product is obtained.

[0031] Step S10: The main component of the mother liquor after lithium precipitation in step S9 is potassium sulfate, which is obtained as a byproduct of potassium sulfate after evaporation and crystallization.

[0032] Compared with related technologies, the lithium mica roasting apparatus and the method for preparing lithium carbonate and producing by-products provided by the present invention have the following beneficial effects:

[0033] This invention provides a lithium mica roasting apparatus and a method for preparing lithium carbonate and producing by-products. The invention utilizes a stirring component to achieve a turning effect during material roasting, improving roasting uniformity and thus enhancing the quality of metal recovery. The receiving box provides a sealing effect during furnace discharge, reducing the entry of cold air into the furnace and preventing severe temperature loss, resulting in energy savings and improved metal recovery efficiency. If blockage occurs during discharge, a clearing component can be activated to clear the blockage, reducing workload and improving operational safety. After discharge, the heat dissipation grooves on the receiving box open to cool the material and prevent burns to workers handling it. The invention, through the cooperation of the pusher and drive components, enables rapid switching between stirring, discharging, and clearing states, integrating multiple functions and switching between different actions in different processes, thus improving ease of use. Attached Figure Description

[0034] Figure 1 This is a schematic diagram of a preferred embodiment of the lithium mica calcination apparatus provided by the present invention.

[0035] Figure 2 This is a side view of the lithium mica calcination apparatus provided by the present invention;

[0036] Figure 3 A cross-sectional schematic diagram of the lithium mica calcination apparatus provided by the present invention;

[0037] Figure 4 for Figure 1 The diagram shows the structure of the discharge assembly.

[0038] Figure 5 for Figure 3 The diagram shows the structure of the stirring assembly.

[0039] Figure 6 for Figure 2 The diagram shows the structure of the heat dissipation component.

[0040] Figure 7 for Figure 3 The diagram shows the structure of the unblocking component.

[0041] Figure 8 for Figure 3 The diagram shows the structure of the driving component.

[0042] Figure 9 This is an initial state diagram of the lithium mica calcination apparatus provided by the present invention;

[0043] Figure 10 This is a schematic diagram showing the state of the pusher component after its initial extension.

[0044] Figure 11This is a schematic diagram showing the state of the pusher component after its secondary extension.

[0045] Numbering on the map:

[0046] 1. Roasting oven; 2. Base;

[0047] 3. Discharge assembly; 31. Discharge chute; 32. Seal; 33. Sealing plate; 34. Displacement frame; 35. Telescopic structure; 351. Piston cylinder; 352. Piston block; 353. First elastic element; 354. Piston rod; 36. L-shaped frame.

[0048] 4. Receiving box;

[0049] 5. Stirring assembly; 51. Stirring shaft; 52. First bevel gear; 53. Stirring disc;

[0050] 6. Heat dissipation assembly; 61. Heat dissipation groove; 62. Filter screen; 63. Mounting bracket; 64. Sliding block; 65. Second elastic element; 66. Baffle plate; 67. Through hole; 68. Inclined block.

[0051] 7. Fixed box;

[0052] 8. Unblocking component; 81. Connecting frame; 82. Sliding plate; 83. Third elastic element; 84. Connecting rod; 85. Connecting plate; 86. Fixing ring; 87. Unblocking cone; 88. Sleeve rod; 89. Cam; 810. Positioning sleeve.

[0053] 9. Drive assembly; 91. Pushing component; 92. Moving plate; 93. Drive rod; 94. Second bevel gear; 95. Positioning block; 96. Connecting plate; 97. Drive component.

[0054] 10. Feed chute, 11. Burner, 12. Flue gas exhaust pipe, 13. Box door. Detailed Implementation

[0055] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0056] Please refer to the following: Figures 1-11 A lithium mica calcination apparatus includes: a calcination furnace 1 and a base 2;

[0057] Discharge assembly 3, which is installed on the roasting furnace 1, is used to discharge the material inside the roasting furnace 1;

[0058] A receiving box 4 is installed at the bottom of the discharging assembly 3. A stirring assembly 5 is installed on the receiving box 4. The stirring assembly 5 passes through the discharging assembly 3 and extends into the interior of the roasting furnace 1. The stirring assembly 5 is used to stir the materials inside the roasting furnace 1.

[0059] Heat dissipation component 6 is installed on the receiving box 4 and is used to dissipate heat from the material discharged into the receiving box 4.

[0060] A fixed box 7 is installed on the base 2, and the top of the fixed box 7 is fixedly connected to the receiving box 4. A clearing component 8 is installed on the fixed box 7. The clearing component 8 passes through the receiving box 4 and extends into the receiving box 4. When the discharging component 3 discharges material, the clearing component 8 is used to clear the blocked material.

[0061] Drive component 9 is mounted on the fixed box 7.

[0062] In this embodiment, all electrical devices of this device are connected to an external power source through a control panel. This is a relatively mature existing technology and will not be described in detail here.

[0063] In this embodiment, the drive component 9 is used to drive and control the stirring component 5, the discharge component 3 and the unblocking component 8. When the discharge component 3 is opened, the heat dissipation component 6 is closed in conjunction with the control component 9 to prevent cold air from entering the receiving box 4 from the heat dissipation component 6.

[0064] In one embodiment, the bottom of the base 2 is provided with lockable casters for easy movement.

[0065] Please refer to the following: Figure 1 , Figure 2 and Figure 3 The top of the roasting furnace 1 is equipped with a feeding trough 10, a burner 11 and a flue gas exhaust pipe 12, and the left side of the receiving box 4 is equipped with a box door 13.

[0066] In this embodiment, the feed trough 10 is provided with an openable cover plate, and the feed trough 10 is used for feeding materials.

[0067] In this embodiment, the burner 11 is a conventional burner used in this field, which only needs to achieve the combustion effect. It is equipped with a fuel supply system, which is a relatively mature technology and will not be described in detail here.

[0068] In this embodiment, the flue gas exhaust pipe 12 is used to discharge the roasting flue gas. The flue gas exhaust pipe 12 can be connected to subsequent flue gas purification equipment to realize the purification of flue gas and the utilization of waste heat.

[0069] Furthermore, a filter structure can be installed at the inlet of the flue gas exhaust pipe 12 to block particulate matter in the flue gas and prevent the flue gas exhaust pipe 12 from being blocked by adhering particles.

[0070] In this embodiment, the door 13 is used to open the receiving box 4, allowing workers to retrieve materials.

[0071] Please refer to the following: Figure 4 The discharge assembly 3 includes a discharge trough 31, a sealing strip 32, a sealing plate 33, a displacement frame 34, a telescopic structure 35, and an L-shaped frame 36. The discharge trough 31 is fixed between the roasting furnace 1 and the receiving box 4. The sealing strip 32 is fixed to the left side of the inner wall of the discharge trough 31. The sealing plate 33 is slidably connected to the discharge trough 31. The displacement frame 34 is fixed to the sealing plate 33. The telescopic structure 35 is installed on the displacement frame 34. The L-shaped frame 36 is slidably connected to the displacement frame 34.

[0072] In this embodiment, a circular hole is formed between the sealing strip 32 and the sealing plate 33, through which the stirring shaft 51 can pass. When the stirring shaft 51 passes through, it cooperates with the sealing strip 32 and the sealing plate 33 to seal the discharge trough 31 (the sealing method is in the form of flange, sealing ring, etc., which is conventional technology in the existing field. Those skilled in the art can choose the optimal solution to implement, including the sealing connection at the through-hole of the shaft workpiece in this embodiment. All are selected according to actual needs and will not be described in detail here).

[0073] In this embodiment, the sealing plate 33 slides inside the discharge trough 31, and the right side of the sealing plate 33 penetrates through the discharge trough 31 and extends to the right side of the discharge trough 31, and the sealing plate 33 does not detach from the discharge trough 31.

[0074] In this embodiment, the bottom of the displacement frame 34 is a straight edge and the right side is a beveled edge. As the displacement frame 34 moves to the right, the beveled edge can press the inclined surface of the inclined block 68, causing the inclined block 68 to move downward. As the displacement frame 34 moves to the right, the straight edge at the bottom can press the inclined block 68 against the position after it has moved downward.

[0075] When the connecting plate 96 moves to the right, causing the L-shaped frame 36 to move to the right, the telescopic structure 35 moves to the right, causing the displacement frame 34 to move to the right, thereby causing the sealing plate 33 to move to the right. At this time, the telescopic structure 35 does not stretch.

[0076] As the sealing plate 33 moves to the right to its maximum stroke, it can no longer move to the right. At this point, the displacement frame 34 can no longer move to the right. When the connecting plate 96 continues to move to the right, the L-shaped frame 36 will slide on the displacement frame 34, causing the telescopic structure 35 to stretch.

[0077] The telescopic structure 35 provides a secondary rightward movement stroke for the connecting plate 96, avoiding motion interference. In other words, it indirectly provides a secondary extension stroke for the pusher 91.

[0078] Please refer to it again. Figure 4The telescopic structure 35 includes a piston cylinder 351, a piston block 352, a first elastic element 353, and a piston rod 354. The piston cylinder 351 is fixed to the displacement frame 34, the piston block 352 is slidably connected inside the piston cylinder 351, the first elastic element 353 is disposed between the piston cylinder 351 and the piston block 352, and the piston rod 354 is fixed to the piston block 352, with one end of the piston rod 354 fixed to the L-shaped frame 36.

[0079] In this embodiment, the first elastic element 353 includes, but is not limited to, springs, elastic ribs, negative pressure telescopic cylinders, etc., as long as it provides a reaction force to the piston block 352 after the piston block 352 moves to the right, so as to facilitate its reset.

[0080] When in use, when the connecting plate 96 moves to the right and drives the L-shaped frame 36 to move to the right, the telescopic structure 35 moves to the right as a whole and drives the displacement frame 34 to move to the right, thereby causing the sealing plate 33 to move to the right to its maximum stroke and opening the discharge chute 31.

[0081] Since the sealing plate 33 has moved to its maximum stroke, when the connecting plate 96 needs to continue to move to the right, the piston rod 354 will only move to the right through the L-shaped bracket 36, so that the piston block 352 slides to the right inside the piston cylinder 351, causing the first elastic element 353 to stretch.

[0082] Please refer to the following: Figure 5 The stirring assembly 5 includes a stirring shaft 51, a first bevel gear 52, and a stirring disc 53. The stirring shaft 51 is rotatably connected to the receiving box 4. The first bevel gear 52 is fixed to the bottom end of the stirring shaft 51, and the stirring disc 53 is fixed to the outer surface of the stirring shaft 51.

[0083] In this embodiment, the bottom end of the stirring shaft 51 passes through the fixed box 7 and extends into the interior of the fixed box 7, with a sealed connection at the penetration point.

[0084] In the initial state, the outer surfaces of the first bevel gear 52 and the second bevel gear 94 are engaged.

[0085] In this embodiment, the number and shape of the mixing discs 53 are not limited, and those skilled in the art can make the best choice according to the actual situation.

[0086] Furthermore, the material of this stirring assembly 5 meets the requirements of the calcination process.

[0087] In use, the drive component 97 drives the drive rod 93 to rotate, which in turn causes the second bevel gear 94 to rotate, thereby driving the first bevel gear 52 to rotate, which in turn drives the stirring shaft 51 to rotate, thereby driving the stirring plate 53 to rotate, realizing the stirring and turning of the material and improving the roasting effect.

[0088] Please refer to the following: Figure 6 The heat dissipation assembly 6 includes a heat dissipation groove 61, a filter screen 62, a mounting bracket 63, a sliding block 64, a second elastic element 65, a baffle plate 66, a through hole 67, and an inclined block 68. The heat dissipation groove 61 is fixed to the receiving box 4, the filter screen 62 is installed in the heat dissipation groove 61, the mounting bracket 63 is fixed to the receiving box 4, the sliding block 64 is slidably connected to the mounting bracket 63, the second elastic element 65 is disposed between the mounting bracket 63 and the sliding block 64, the baffle plate 66 is fixed to the top of the sliding block 64 and the baffle plate 66 is in contact with the heat dissipation groove 61, the through hole 67 is opened on the baffle plate 66, and the inclined block 68 is fixed on the baffle plate 66.

[0089] In this embodiment, a sealing element is provided on the left side of the shielding plate 66, which can play a sealing role when it shields the heat dissipation groove 61.

[0090] In this embodiment, the second elastic element 65 may include, but is not limited to, a spring, an elastic rib, or a negative pressure telescopic cylinder, etc. It only needs to provide elastic support for the sliding block 64 and provide a reverse elastic force when the sliding block 64 moves downward.

[0091] The filter 62 can prevent dust and material splashing.

[0092] In one embodiment, the filter 62 is detachably connected to the heat dissipation groove 61. The detachment method can be bolt-on or snap-on, and the filter 62 can be removed and replaced.

[0093] Please refer to the following: Figure 10 When the discharge chute 31 is in the open state, the heat dissipation chute 61 is in the closed state, so that cold air will not enter from the heat dissipation chute 61 during material discharge, thus preventing cold air from entering the furnace body.

[0094] Please refer to the following: Figure 9 When the discharge chute 31 is in a closed state, the heat dissipation trough 61 is in an open state. This can also be understood as the discharge chute 31 is opened and closed after the material discharge is completed, and the material falls into the receiving box 4. Opening the heat dissipation trough 61 is conducive to the cooling of the material.

[0095] In one embodiment, the heat dissipation groove 61 can also be connected to a suction device, which can work with the suction device to quickly extract hot air from inside the receiving box 4.

[0096] Please refer to the following: Figure 7The unblocking component 8 includes a connecting frame 81, a sliding plate 82, a third elastic element 83, a connecting rod 84, a connecting plate 85, a fixing ring 86, an unblocking cone 87, a sleeve rod 88, a cam 89, and a positioning sleeve 810. The connecting frame 81 is fixed inside the fixing box 7. The sliding plate 82 is slidably connected inside the connecting frame 81. The third elastic element 83 is disposed between the connecting frame 81 and the sliding plate 82. The connecting rod 84 is fixed on the sliding plate 82. The connecting plate 85 is fixed on the top end of the connecting rod 84. The fixing ring 86 is fixed on the connecting plate 85. The unblocking cone 87 is fixed on the fixing ring 86. The sleeve rod 88 is rotatably connected to the connecting frame 81. The cam 89 is fixed on the outer surface of the sleeve rod 88. The positioning sleeve 810 is fixed to one end of the sleeve rod 88.

[0097] In this embodiment, the third elastic element 83 includes, but is not limited to, springs, elastic ribs, negative pressure telescopic cylinders, etc. It only needs to provide a reaction force to the sliding plate 82 after the sliding plate 82 moves upward, so that the sliding plate 82 can be reset more stably.

[0098] In one embodiment, the third elastic element 83 may not be installed between the sliding plate 82 and the connecting frame 81, and the sliding plate 82 may be reset by gravity after moving upward.

[0099] In this embodiment, the top end of the connecting rod 84 passes through the connecting frame 81, the fixing box 7 and the receiving box 4 in sequence and extends into the interior of the receiving box 4, with a sealed connection at the penetration point.

[0100] In this embodiment, both ends of the sleeve rod 88 penetrate the connecting frame 81 and extend to the outside of the connecting frame 81, and the right end of the sleeve rod 88 also penetrates the fixing box 7 and extends to the outside of the fixing box 7. The inside of the sleeve rod 88 is hollow.

[0101] Furthermore, the drive rod 93 passes through the inside of the sleeve rod 88 and slides in a horizontal direction.

[0102] In this embodiment, the positioning block 95 and the positioning sleeve 810 are compatible and can be snapped together.

[0103] Preferably, there are four unblocking cones 87, but the number can be adjusted according to actual needs.

[0104] In use, after the pusher 91 extends for the second time, it will drive the drive rod 93 to move to the right, thereby causing the positioning block 95 to engage with the positioning sleeve 810. Then, the drive member 97 rotates, causing the drive rod 93 to rotate, which in turn causes the positioning block 95 to rotate, causing the positioning sleeve 810 to rotate, thereby causing the sleeve rod 88 to drive the cam 89 to rotate, indirectly realizing the up-and-down reciprocating motion of the unblocking cone 87.

[0105] In this embodiment, when the drive rod 93 moves to the right, the positioning block 95 engages with the positioning sleeve 810, and the second bevel gear 94 is separated from the first bevel gear 52. When the drive member 97 rotates, it will drive the cam 89 independently and will not drive the stirring shaft 51 to rotate, thus avoiding power reduction and improving the unblocking force.

[0106] Please refer to the following: Figure 8 The drive assembly 9 includes a pusher 91, a movable plate 92, a drive rod 93, a second bevel gear 94, a positioning block 95, a connecting plate 96, and a drive member 97. The pusher 91 is fixed to the fixed box 7. The movable plate 92 is fixed to the output end of the pusher 91 and is slidably connected to the fixed box 7. The drive rod 93 is rotatably connected to the movable plate 92. The second bevel gear 94 and the positioning block 95 are both fixed to the outer surface of the drive rod 93. The connecting plate 96 is rotatably connected to the drive rod 93 and is slidably connected to the base 2. The drive member 97 is mounted on the connecting plate 96, and the output shaft of the drive member 97 is fixedly connected to the drive rod 93.

[0107] Furthermore, the left side of the connecting plate 96 is fixedly connected to the right side of the L-shaped frame 36.

[0108] In this embodiment, the pushing component 91 may include, but is not limited to, electric push rods, cylinders, hydraulic cylinders or linear motors, etc., as long as it can drive the moving plate 92 to move linearly in the horizontal direction.

[0109] In this embodiment, the driving component 97 may include, but is not limited to, a motor, a pneumatic motor, or a hydraulic motor, as long as it can provide a driving force for rotation of the driving rod 93.

[0110] In one embodiment, a limiting sliding structure is provided between the drive rod 93 and the sleeve rod 88. The limiting sliding structure includes at least one groove and a slider. The groove is formed on the inner surface of the sleeve rod 88, and the slider is fixedly connected to the outer surface of the drive rod 93 and slidably connected in the groove.

[0111] This limiting sliding structure can ensure that the drive rod 93 slides stably and horizontally inside the sleeve 88, and can drive the sleeve 88 to rotate when the drive rod 93 rotates.

[0112] The working principle of the lepidolite roasting apparatus and the method for preparing lithium carbonate and producing by-products provided by this invention is as follows:

[0113] The material is fed into the roasting furnace 1 from the feed trough 10 for roasting. The rotation of the drive component 97 drives the drive rod 93 to rotate, thereby causing the second bevel gear 94 to rotate and drive the first bevel gear 52 to rotate, which in turn causes the stirring shaft 51 to rotate and drive the stirring plate 53 to rotate, thus stirring the material inside.

[0114] After the material is roasted, the extension of the pusher 91 causes the moving plate 92 to move to the right, which in turn causes the drive rod 93 to move to the right, thereby causing the second bevel gear 94 to separate from the first bevel gear 52. The rightward movement of the drive rod 93 also causes the connecting plate 96 to move to the right, which in turn causes the L-shaped frame 36 to move to the right. This, in turn, causes the displacement frame 34 to move to the right through the telescopic structure 35, which in turn causes the sealing plate 33 to move to the right, opening the discharge chute 31 and allowing the material to be discharged from the roasting furnace 1 into the receiving box 4.

[0115] During the above material discharge process, as the displacement frame 34 moves to the right, it will press the baffle plate 66 downward through the inclined block 68, thereby causing the baffle plate 66 to move downward, causing the through hole 67 to move downward and misalign with the heat dissipation groove 61, thereby sealing the receiving box 4 and reducing the entry of cold air.

[0116] During material discharge, if material bridging and blockage occur, the extension of the pusher 91 causes the moving plate 92 to continue moving to the right, which in turn causes the drive rod 93 to move to the right again, causing the positioning block 95 to engage with the positioning sleeve 810. However, the connecting plate 96 continues to move to the right, causing the L-shaped frame 36 to move to the right. At this time, the telescopic structure 35 is stretched, and the displacement frame 34 continues to press down on the inclined block 68. When the positioning block 95 engages with the positioning sleeve 810, the rotation of the drive member 97 causes the drive rod 93 to rotate, which in turn causes the positioning block 95 to rotate, which in turn causes the positioning sleeve 810 to rotate, which in turn causes the sleeve rod 88 to rotate, which in turn causes the cam 89 to rotate, which in turn causes the sliding plate 82 to move up and down. This, in turn, causes the fixed ring 86 to move up and down through the connecting rod 84 and the connecting plate 85, which in turn causes the unblocking cone to move up and down, thus clearing the material blocked at the outlet of the discharge chute 31.

[0117] After the material discharge is completed, the pusher 91 retracts and resets, causing the sealing plate 33 to move to the left to re-seal the discharge chute 31, and causing the baffle plate 66 to move upward and reset, so that the through hole 67 is aligned with the heat dissipation groove 61, which facilitates the cooling of the material inside the receiving box 4. After cooling is completed, the box door 13 can be opened to take out the material.

[0118] Compared with related technologies, the lithium mica roasting apparatus and the method for preparing lithium carbonate and producing by-products provided by the present invention have the following beneficial effects:

[0119] This invention, through the setting of the stirring component 5, can achieve a turning effect during material roasting, improving roasting uniformity and thus improving the quality of metal material recycling. The setting of the receiving box 4 can achieve a sealing effect during material discharge from the roasting furnace 1, reducing the entry of cold air into the furnace body, thereby avoiding the problem of severe temperature loss in the roasting furnace 1, achieving energy saving and improving metal recycling efficiency. If blockage occurs during discharge, the unblocking component 8 can be driven to clear the material, reducing the workload of workers and improving operational safety. After discharge, the heat dissipation groove 61 on the receiving box 4 will open to cool the material and prevent workers from being burned while handling it. Through the cooperation of the pushing component 91 and the driving component 97, this invention can achieve rapid switching between stirring, discharging, and unblocking states, integrating multiple functions into one device, switching different actions in different processes, and improving ease of use.

[0120] In one instance, this roasting apparatus can be used to roast lepidolite in a method for preparing lithium carbonate from lepidolite and producing by-products.

[0121] In another case, this roasting apparatus can be used for roasting materials in lithium smelting slag to recover useful metals.

[0122] This invention also provides a method for preparing lithium carbonate from lepidolite and producing by-products, comprising the following steps:

[0123] Example 1

[0124] Step S1: Weigh 1000g of crushed and ball-milled lepidolite concentrate and mix it with 75wt% dilute sulfuric acid at an acid-ore mass ratio of 1.2:1. The mixture is then subjected to low-temperature roasting at 280℃ for 3 hours in the roasting device to obtain roasted clinker. During the roasting process, the lepidolite lattice is destroyed, and elements such as lithium, aluminum, potassium, rubidium, and cesium are converted into soluble sulfates.

[0125] Step S2: The roasted clinker is stirred and leached at 60°C for 2 hours at a solid-liquid ratio of 1:4. After leaching, solid-liquid separation is performed to obtain leaching residue and leaching brine containing lithium, aluminum, potassium, rubidium, and cesium.

[0126] Step S3: Wash the leaching residue with water at a solid-liquid ratio of 1:4 twice to obtain first wash water, second wash water and washed residue. The first wash water is returned to step S2 for leaching, and the second wash water is used as the first wash repeatedly. The main component of the washed residue is silica sand, which can be recycled as a building material raw material.

[0127] Step S4: Add potassium hydroxide to the leaching brine obtained in step S2 to adjust the pH to 2.5, then cool to 18°C ​​and crystallize at a constant temperature for 60 min to precipitate rubidium cesium alum crystals. Filter to recover rubidium cesium vanadium. Continue to cool the filtrate to 5°C and crystallize at a constant temperature for 75 min to precipitate potassium alum crystals. Filter to recover potassium alum to obtain filtrate A.

[0128] Step S5: Add calcium oxide slurry to filtrate A, adjust the pH to 6.0, stir and react at 60°C for 40 min, so that iron ions and residual aluminum ions precipitate in the form of hydroxides, and filter to obtain iron-aluminum-fluorine filter residue and filtrate B.

[0129] Step S6: Continue to add calcium oxide slurry to filtrate B, adjust the pH to 11.5, stir and react at 80℃ for 40 min to precipitate magnesium ions and manganese ions into magnesium hydroxide and manganese hydroxide, and filter to obtain magnesium-manganese filter residue and filtrate C.

[0130] Step S7: Add potassium carbonate to filtrate C, stir and react at 68°C for 60 min, react with calcium ions in the solution to form calcium carbonate precipitate, filter to obtain calcium-containing filter residue and filtrate D;

[0131] Step S8: The filtrate D is deeply purified by passing it through an ion exchange resin to remove residual trace impurity metal ions, resulting in a pure lithium sulfate solution E.

[0132] Step S9: Carbon dioxide is introduced into solution E at room temperature to carry out a carbonation reaction for 3 hours. After the reaction is completed, the temperature is raised to 95°C and reacted for 2 hours to generate lithium carbonate precipitate. After filtration, washing and drying, battery-grade lithium carbonate product is obtained.

[0133] Step S10: The main component of the mother liquor after lithium precipitation in step S9 is potassium sulfate. After evaporation and crystallization, potassium sulfate by-product is obtained, which can be sold as agricultural potassium fertilizer.

[0134] Example 2

[0135] Step S1: Weigh 1000g of crushed and ball-milled lepidolite concentrate and mix it with 80wt% dilute sulfuric acid at an acid-ore mass ratio of 1.1:1. The mixture is then subjected to low-temperature roasting at 280℃ for 3 hours in the roasting device to obtain roasted clinker. During the roasting process, the lepidolite lattice is destroyed, and elements such as lithium, aluminum, potassium, rubidium, and cesium are converted into soluble sulfates.

[0136] Step S2: The roasted clinker is stirred and leached at 60°C for 2 hours at a solid-liquid ratio of 1:5. After leaching, solid-liquid separation is performed to obtain leaching residue and leaching brine containing lithium, aluminum, potassium, rubidium, and cesium.

[0137] Step S3: Wash the leaching residue with water at a solid-liquid ratio of 1:5 twice to obtain first wash water, second wash water and washed residue. The first wash water is returned to step S2 for leaching, and the second wash water is used as the first wash repeatedly. The main component of the washed residue is silica sand, which can be recycled as a building material raw material.

[0138] Step S4: Add potassium hydroxide to the leaching brine obtained in step S2 to adjust the pH to 2.0, then cool to 18°C ​​and crystallize at a constant temperature for 60 min to precipitate rubidium cesium alum crystals. Filter to recover rubidium cesium vanadium. Continue to cool the filtrate to 5°C and crystallize at a constant temperature for 75 min to precipitate potassium alum crystals. Filter to recover potassium alum to obtain filtrate A.

[0139] Step S5: Add calcium oxide slurry to filtrate A, adjust the pH to 6.0, stir and react at 60°C for 40 min, so that iron ions and residual aluminum ions precipitate in the form of hydroxides, and filter to obtain iron-aluminum-fluorine filter residue and filtrate B.

[0140] Step S6: Add calcium oxide slurry to filtrate B, adjust pH to 12, stir and react at 80°C for 40 min to precipitate magnesium and manganese ions as magnesium hydroxide and manganese hydroxide, and filter to obtain magnesium and manganese filter residue and filtrate C.

[0141] Step S7: Add potassium carbonate to filtrate C, stir and react at 68°C for 60 min, react with calcium ions in the solution to form calcium carbonate precipitate, filter to obtain calcium-containing filter residue and filtrate D;

[0142] Step S8: The filtrate D is deeply purified by passing it through an ion exchange resin to remove residual trace impurity metal ions, resulting in a pure lithium sulfate solution E.

[0143] Step S9: Carbon dioxide is introduced into solution E at room temperature to carry out a carbonation reaction for 3 hours. After the reaction is completed, the temperature is raised to 95°C and reacted for 2 hours to generate lithium carbonate precipitate. After filtration, washing and drying, battery-grade lithium carbonate product is obtained.

[0144] Compared with related technologies, the lithium mica roasting apparatus and the method for preparing lithium carbonate and producing by-products provided by the present invention have the following beneficial effects:

[0145] This invention employs a low-temperature sulfuric acid roasting process at 260-350℃, which significantly reduces energy consumption compared to the high-temperature roasting above 900℃ in the traditional sulfate method. Simultaneously, since no auxiliary materials such as sodium sulfate and potassium sulfate are required, the amount of smelting slag is reduced by more than 50%, and the concentrations of sodium and potassium in the leachate are significantly lower, reducing the burden on subsequent purification.

[0146] Utilizing the difference in solubility of rubidium-cesium alum and potassium alum within different temperature ranges, a two-stage freeze-crystallization process achieves efficient separation and recovery of rubidium, cesium, aluminum, and potassium. High-purity rubidium-cesium alum precipitates at 18-20℃, while potassium alum precipitates at 0-8℃. This process not only recovers the valuable rare and precious metals rubidium and cesium but also removes over 85% of aluminum impurities, creating favorable conditions for subsequent purification. Compared to existing technologies, this process eliminates the need for complex extraction steps, simplifying the process flow.

[0147] This invention not only extracts lithium carbonate from lepidolite resources, but also simultaneously recovers rubidium-cesium alum (which can be further processed into high-purity rubidium-cesium salts), potassium alum, potassium sulfate, and silica sand, among other high-value byproducts. Through comprehensive utilization of these byproducts, even without considering the value of rubidium-cesium salts, the cost of lithium extraction from lepidolite can be brought close to that from salt lakes, resulting in significant economic benefits.

[0148] This invention uses potassium hydroxide, calcium oxide, and potassium carbonate to adjust the pH value in steps, removing impurity ions such as iron, aluminum, magnesium, manganese, and calcium in different pH ranges. This avoids the lithium entrainment loss in the traditional single neutralization and impurity removal process and improves the lithium recovery rate.

[0149] The above description is merely an embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural or procedural transformations made based on the content of the present invention specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of the present invention.

Claims

1. A lithium mica calcination apparatus, characterized in that, include: roasting oven and base; A discharge assembly is installed on the roasting furnace and is used to discharge materials inside the roasting furnace. A receiving box is installed at the bottom of the discharging assembly. A stirring assembly is installed on the receiving box. The stirring assembly passes through the discharging assembly and extends into the interior of the roasting furnace. The stirring assembly is used to stir the materials inside the roasting furnace. A heat dissipation component is installed on the receiving bin and is used to dissipate heat from the material discharged into the receiving bin. A fixed box is installed on the base, and the top of the fixed box is fixedly connected to the receiving box. A clearing component is installed on the fixed box, which passes through the receiving box and extends into the receiving box. When the discharging component discharges material, the clearing component is used to clear the blockage. A drive assembly, which is mounted on the fixed housing.

2. The lithium mica calcination apparatus according to claim 1, characterized in that, The top of the roasting furnace is equipped with a feeding trough, a burner, and a flue gas exhaust pipe, and the left side of the receiving box is equipped with a box door.

3. The lithium mica calcination apparatus according to claim 1, characterized in that, The discharge assembly includes a discharge trough, a sealing strip, a sealing plate, a displacement frame, a telescopic structure, and an L-shaped frame. The discharge trough is fixed between the roasting furnace and the receiving box. The sealing strip is fixed to the left side of the inner wall of the discharge trough. The sealing plate is slidably connected to the discharge trough. The displacement frame is fixed to the sealing plate. The telescopic structure is installed on the displacement frame. The L-shaped frame is slidably connected to the displacement frame.

4. The lithium mica calcination apparatus according to claim 3, characterized in that, The telescopic structure includes a piston cylinder, a piston block, a first elastic element, and a piston rod. The piston cylinder is fixed to the displacement frame, the piston block is slidably connected inside the piston cylinder, the first elastic element is disposed between the piston cylinder and the piston block, and the piston rod is fixed to the piston block, with one end of the piston rod fixed to the L-shaped frame.

5. The lithium mica calcination apparatus according to claim 1, characterized in that, The mixing assembly includes a mixing shaft, a first bevel gear, and a mixing disc. The mixing shaft is rotatably connected to the receiving box, the first bevel gear is fixed to the bottom end of the mixing shaft, and the mixing disc is fixed to the outer surface of the mixing shaft.

6. The lithium mica roasting apparatus according to claim 1, characterized in that, The heat dissipation assembly includes a heat dissipation groove, a filter screen, a mounting bracket, a sliding block, a second elastic element, a baffle plate, a through hole, and an inclined block. The heat dissipation groove is fixed to the receiving box, the filter screen is installed in the heat dissipation groove, the mounting bracket is fixed to the receiving box, the sliding block is slidably connected to the mounting bracket, the second elastic element is disposed between the mounting bracket and the sliding block, the baffle plate is fixed to the top of the sliding block and is in contact with the heat dissipation groove, the through hole is opened on the baffle plate, and the inclined block is fixed to the baffle plate.

7. The lithium mica roasting apparatus according to claim 1, characterized in that, The unblocking assembly includes a connecting frame, a sliding plate, a third elastic element, a connecting rod, a connecting plate, a fixing ring, an unblocking cone, a sleeve, a cam, and a positioning sleeve. The connecting frame is fixed inside the fixing box, the sliding plate is slidably connected inside the connecting frame, the third elastic element is disposed between the connecting frame and the sliding plate, the connecting rod is fixed to the sliding plate, the connecting plate is fixed to the top end of the connecting rod, the fixing ring is fixed to the connecting plate, the unblocking cone is fixed to the fixing ring, the sleeve is rotatably connected to the connecting frame, the cam is fixed to the outer surface of the sleeve, and the positioning sleeve is fixed to one end of the sleeve.

8. The lithium mica calcination apparatus according to claim 7, characterized in that, The drive assembly includes a pusher, a movable plate, a drive rod, a second bevel gear, a positioning block, a connecting plate, and a drive component. The pusher is fixed to the fixed box, the movable plate is fixed to the output end of the pusher and slidably connected to the fixed box, the drive rod is rotatably connected to the movable plate, the second bevel gear and the positioning block are both fixed to the outer surface of the drive rod, the connecting plate is rotatably connected to the drive rod and slidably connected to the base, the drive component is mounted on the connecting plate, and the output shaft of the drive component is fixedly connected to the drive rod.

9. A method for preparing lithium carbonate from lepidolite and simultaneously producing by-products, characterized in that, Includes the following steps: Step S1: The crushed and ball-milled lithium mica concentrate is mixed with dilute sulfuric acid and then roasted at low temperature in the roasting apparatus described in any one of claims 1-8 to obtain roasted clinker; Step S2: Stir and leach the roasted clinker. After leaching, perform solid-liquid separation to obtain leaching residue and leaching brine containing lithium, aluminum, potassium, rubidium, and cesium. Step S3: Wash the leaching residue twice to obtain first wash water, second wash water and washed residue. Return the first wash water to step S2 for leaching, and repeat the second wash water as the first wash. Step S4: Add potassium hydroxide to the leaching brine obtained in step S2 to adjust the pH to 2-3, then cool to 18-20℃ and crystallize at a constant temperature to precipitate rubidium and cesium alum crystals. Filter to recover rubidium and cesium vanadium. Continue to cool the filtrate to 0-8℃ and crystallize at a constant temperature to precipitate potassium alum crystals. Filter to recover potassium alum to obtain filtrate A. Step S5: Add calcium oxide slurry to filtrate A, adjust the pH to 6-6.5, stir the reaction to precipitate iron ions and residual aluminum ions in the form of hydroxides, and filter to obtain iron-aluminum-fluorine filter residue and filtrate B. Step S6: Continue to add calcium oxide slurry to filtrate B, adjust the pH to 11.5-12, stir the reaction to precipitate magnesium ions and manganese ions into magnesium hydroxide and manganese hydroxide, and filter to obtain magnesium-manganese filter residue and filtrate C. Step S7: Add potassium carbonate to filtrate C, stir to react, and react with calcium ions in the solution to form calcium carbonate precipitate. Filter to obtain calcium-containing filter residue and filtrate D. Step S8: The filtrate D is deeply purified by passing it through an ion exchange resin to remove residual trace impurity metal ions, resulting in a pure lithium sulfate solution E. Step S9: Carbon dioxide is introduced into solution E at room temperature to carry out a carbonation reaction. After the reaction is completed, the temperature is raised to 80-95℃ and the reaction is carried out again to generate lithium carbonate precipitate. After filtration, washing and drying, battery-grade lithium carbonate product is obtained. Step S10: The main component of the mother liquor after lithium precipitation in step S9 is potassium sulfate, which is obtained as a byproduct of potassium sulfate after evaporation and crystallization.

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